Idema was known in Afghanistan as a mysterious figure, often seen clad in combat gear and dark glasses and heavily armed.

He was one of many former special forces soldiers working privately in Afghanistan - some to provide security, others acting as bounty hunters attracted by the millions of dollars in rewards offered for Osama Bin Laden and other top al-Qaeda men.

Ties denied

The three men were arrested in July 2004 after Afghan forces raided a house in a Kabul neighbourhood and discovered eight Afghan men being held captive.

Idema said his group was tracking down terror suspects with the co-operation of Afghan and US authorities.

The US said it had received one prisoner from Idema but the Pentagon denied any ties to him.

Nato forces also said they had been duped into helping the group on three occasions.

Correspondents say their trial was often chaotic and marred by poor translation.

Defence lawyers said the Afghan legal system was not fit to try the men.

The Americans are serving their sentences in Kabul's Pul-e Charkhi prison. They have a heated and carpeted cell with satellite television.